Topic: Does this look right?

[danielbholmes]

I just purchased a Helix 7 SI. The side imaging seems really unclear and rather noisy.

Some background info: My local lake is a shallow, weedy lake, that averages 3-8 feet deep, with a soft, muddy bottom. I'm in Massachusetts so a lot of the weeds haven't reached the surface yet. The transducer is mounted on the stern of the boat (a 14 foot aluminum jon boat) according to the instructions...choosing the least turbulent spot on the stern. There is about an 8 inch gap between the stern and the back of the outboard and trolling motor for the SI to see on either side. The transducer is on the starboard side. The trolling motor is on the port. The trolling motor and Helix are both connected to the same battery. The outboard was not running during my tests.

Do these screens (below) look normal for the conditions I've described or should I be troubleshooting something? They don't seem very clear to me.

[sonar2000]

Not bad for the shallow depth.  Couple of things. What was the speed of the boat during the run? Also could be just a small bounce of the transducer, could there have been some waves or wind? I would not expect much more from the 2 feet depth.  the 7 foot looks better...
Chuck

[danielbholmes]

Thanks for the reply Chuck. The speed was averaging 1-3mph. I think I have my chart speed at 2 or 3. The bounce could be a real possibility because I haven't put the third screw into the transducer mount (and there is a little slop) as I think the instructions said to take the boat out and make sure it was working properly before locking screwing the third screw in. It was also windy and choppy. Should I be setting my range a lot shorter for shallow lakes like that? How come it lacks the clarity that see in some other people's screen shots...is it the weedy soft bottom nature of this lake? It seems so noisy (for lack of a better term)....

[sonar2000]

For shallow water (less than 5 feet) you might want to set the side distance to maybe 3 to 4 time the depth. Boat speed looked good and the chart speed looked good. I have seen over the years that the side imaging for less than 10 feet is not as good or as clear until you get above that. I would certainly try setting the side distance quite a bit less. And when you can get the transducer bounce taken care of it may help. I had my transducers set about 8 inches  below the boat bottom using a metal bracket. Of course this will place extra burden on you to keep from running the transducer into the ground especially in shallow water. The bracket I made also has a kickup feature in case I do rub or bump into something. Todays mounting is using a trolling motor mounting system minus the motor. This lets me kick up the transduce when I see the depth going less than 1 foot. We just have to be creative for the purposes for which we use the system..  Chuck

[danielbholmes]

Good advice. Thanks Chuck.

[danielbholmes]

Chuck, do you find getting the transducer a bit deeper gives you better results in shallow water?

[sonarbear]

To be honest, I find the images really bad. Ok, 2 foot depth, good that there's anything, but the 6 foot depth is also blurry and noisy at the same time. Is the contrast and sharpening maybe turned up to much? If I look at these image, I'm glad I went for the used 898 istead of the new helix

[danielbholmes]

There is a little sharpening, but not much. I'm gonna try another lake this week that is deeper with a harder bottom and see what that looks like.....

[Bob B]

You will never get sharp returns from a shallow WEEDY bottom with SI.  Your image does look like the SI enhance is turned up a little also.

[danielbholmes]

Is there a best practice for settings in shallow weedy lakes with the side imaging?

[sonar2000]

Placing the transducer lower takes away some of the bounce. Wont help much with shallow water but lessens the effects of wind and waves...Chuck

[Rickard]

I have done alot of scanning in such weedy depths. I find your results normal and good.
/Rickard

[danielbholmes]

Thanks for the input, everyone. I will post my screenshots from the deeper, less weedy lake when I get back from there.